With plans to bring his new biotech venture public, Sam Waksal reflected on the past decade, nearly half of which was spent behind bars for an insider trading scandal at his former company ImClone Systems that also ensnared his friend Martha Stewart.

"Any event in life changes one. That was an event that probably changed me in many ways. I think I am a better person," he told CNBC on Tuesday.

In late 2001, in the days before the Food and Drug Administration rejected ImClone's application for the cancer drug Erbitux, Waksal tried to sell stock and communicated with family members, according to the Securities and Exchange Commission. Shares of ImClone tanked on news of the rejection.

Stewart also sold ImClone shares, based on information illegally gleaned from her broker, according to the SEC. She served five months in federal prison and time on house arrest.

Waksal was sentenced in 2003 and got out of prison in 2009, the year after ImClone was sold to Eli Lilly for $6.5 billion and five years after Erbitux eventually gained FDA approval.

"I think I'm probably [now] a more introspective person," he said in a "Squawk Box" interview from the annual JPMorgan health-care conference in San Francisco. "And it's helped shape how we're building Kadmon in many ways."

Kadmon, founded by Waksal in 2010, is preparing for an initial public offering. The company, like ImClone, is working on cancer treatments but also autoimmune regimes. Kadmon has a number of products in midstage clinical trials, said Waksal, who is chairman because a SEC ban prohibits him from serving as an officer or director of any public company.

"I'm not running the show any longer," he said. "I'm going to be the chief of innovation, strategy and science."

Waksal brought in as CEO his brother, Harlan, who co-founded and had helped run ImClone. "He built ImClone with me. We worked together for 25 years. … I couldn't find anyone better to join the company to really more forward the vision."

Never one to mince words, Waksal said he thinks Kadmon will become the "most important biotechnology company of the 21st century."

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